A 13GB database containing around 85,000 images and 9,000 videos was shared online through Reddit and 4chan forums(Reuters)

A month on from the theft and publication of 85,000 private images, Snapchat has issued a fresh warning against using third party applications.

In a blog post the ephemeral image sharing service distanced itself from developers looking to "trick" Snapchat users into handing over their private photos. From now on, users found to be using third party apps will be alerted by Snapchat and asked to change their password.

"We've enjoyed some of the ways that developers have tried to make Snapchat better," the company said. "Unfortunately, some developers build services that trick Snapchatters and compromise their accounts."

Starting this week, the service will alert users "when we have detected that they may be using third-party apps and we'll ask those Snapchatters to change their password and stop using unauthorised apps." The blog post also teased that some "incredible new stuff" is on the way.

In October, an event dubbed The Snappening saw a 13.6GB file containing 85,000 images and 9,000 videos shared through forums on Reddit and 4chan. Many of the images were claimed to contain child pornography and the content was stolen from victims using third party apps such as Snapsave; those using Snapchat's own application were not affected.

It was claimed the images were collected over a number of years through apps which allow users to save images and videos. A unique feature of Snapchat's own application is how shared content is automatically deleted after just a few seconds, as dictated by the sender; if screen-grabbed by the recipient, the sender is alerted.

"We can confirm that Snapchat's servers were never breached and were not the source of these leaks," the firm said in a statement after the incident, adding: "Snapchatters were victimised by their use of third-party apps to send and receive Snaps, a practice that we expressly prohibit in our Terms of Use precisely because they compromise our users' security."